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Feasibility of Biological Treatment of
Potato Processing Wastes
Peter F. Atkins, Jr., Assistant Professor
Otis J. Sproul, Associate Professor
Department of Civil Engineering,
University of Maine
Orono, Maine
INTRODUCTION
The potato processing industry has grown very rapidly from 1956 when 10.1
per cent of the United States potato crop was processed for food to 1962 when 20.4
er cent of the crop was processed.   In the same period French fry production rose
y nearly 380 per cent (1).
These processing plants are and must be located in essentially rural areas in
the potato processing states. These rural areas frequently do not have waste treatment plants. When they are present the additional amount of this high organic
content waste may seriously overload them. The use of the lye peeling process
yields a waste with a high pH. The magnitude of the problem in these rural areas
has caused much concern in the potato processing states.
OBJECTIVE AND SCOPE OF INVESTIGATION
It was the objective of this research to investigate the feasibility of biological
treatment for a combined potato processing waste from a plant practicing lye
peeling of the potato. A detailed study was made of the complete mixed activated sludge method and also a brief investigation of the potential use of the contact stabilization method. Data on waste characteristics from these plants were
also obtained.
LITERATURE REVIEW
The characteristics of potato flake processing wastes have been reviewed by
Francis (2). The average volume of waste per ton of potatoes processed was 5, 000
gallons while the average biochemical oxygen demand (BOD) was 1, 770 mg/1.
The average pH of 11. 7 was caused by the lye peeling operations in each of the
plants studied. Porges and Towne (3) reported a waste flow of 1, 990 gals per
1, 000 lbs of potatoes processed with a BOD of 1, 380 mg/1 in the manufacture of
potato chips.
Francis (2), based on laboratory studies, indicated that BOD and suspended
solids reductions of approximately 30 per cent and 57 per cent respectively can be
expected by plain sedimentation of these wastes. Vennes and Olmstead (4) concluded that lye peeled potato wastes, when reduced to a pH of 10. 2, permitted
the optimum growth of acid producing organisms. The reduction of pH could be
accomplished by chemical or physical means.
Protein water from the manufacture of potato starch has been reported to be
amenable to treatment by standard biological treatment processes (5). BOD removals of 95 per cent were obtained by activated sludge treatment at loadings of
80 lbs of BOD per 1, 000 lbs of MLSS per hr of aeration.    High rate   trickling
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